Mhc-E polymorphism in Pongidae primates: the same allele is found in two different species.
Mhc-E intron 1, exon 2, intron 2, and exon 3 from pygmy chimpanzee (Pan paniscus), chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla) and orangutan (Pongo pygmaeus) have been sequenced; six new Mhc-E alleles have been obtained but sequence changes are only placed either in introns or in synonymous exonic bases. One pygmy chimpanzee Mhc-E DNA sequence is identical to another sequence from chimpanzee; the fact that no variation is found also at the intronic level suggests that these two species of chimpanzee may have recently separated and/or that both of them might only represent subspecies. Mhc-E phylogenetic trees separate two evolutionary groups: Pongidae, including humans, and Cercopithecinae; this is also found by studying another non-classical class I gene, Mhc-G. The Mhc-E alleles' invariance at the protein level supports that strong selective forces are operating at the Mhc-E locus, as has also been found in both Cercopithecinae and humans. These allelic and evolutionary data suggest an altogether different functionality for HLA-E (and also HLA-G) compared with classical class I proteins: i.e., sending negative (tolerogenic) signals to NK and T cells.
Suárez
B
B
Department of Immunology, Hospital 12 de Octubre, Universidad Complutense, Madrid, Spain.
Morales
P
P
Castro
M J
MJ
Fernández-Soria
V
V
Recio
M J
MJ
Pérez-Blas
M
M
Alvarez
M
M
Díaz-Campos
N
N
Arnaiz-Villena
A
A
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D002461:Cell Line, Transformed; D018076:DNA, Complementary; D006071:Gorilla gorilla / Q000235:genetics* / Q000276:immunology; D006680:HLA Antigens / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D015186:Hominidae / Q000235:genetics / Q000276:immunology; D006801:Humans; D008285:Major Histocompatibility Complex; D008969:Molecular Sequence Data; D019974:Pan paniscus / Q000235:genetics* / Q000276:immunology; D002679:Pan troglodytes / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011148:Pongo pygmaeus / Q000235:genetics* / Q000276:immunology; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D000097625:HLA-E Antigens
D018076:DNA, Complementary; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D000097625:HLA-E Antigens